Abstract
Nowadays, rationally preparing heterostructure materials can not only make up for the shortage of individual components, but also exert unexpected performance through synergistic interactions between the components. Herein, a core-shell of WS2@NiCo2O4 screw-like heterostructure arrays grown on carbon cloth (CC) was prepared by a two-step solvothermal method for supercapacitors. As a binder-free flexible electrode, a high areal capacitance of 2449.9 mF cm-2 can be achieved for WS2@NiCo2O4/CC at a current density of 1 mA cm-2. Benefiting from the core-shell of the WS2@NiCo2O4 heterostructure, the capacitive property of the flexible WS2@NiCo2O4/CC electrode is better than those of WS2/CC and NiCo2O4/CC electrodes. Based on WS2@NiCo2O4/CC electrodes, the assembled flexible solid-state symmetric supercapacitor (FSS) device shows a high energy density of ∼45.67 W h kg-1 at a power density of 992.83 W kg-1. Meantime, the WS2@NiCo2O4/CC-assembled FSS device also exhibits high cycling stability with an excellent capacity retention of ∼85.59% after 5000 cycles.